package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {

    /*
    * 开始时间戳
    * */
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    /*
    * 序列号位数*/
    private static final int COUNT_BITS = 32;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public  long nextId(String keyPrefix){
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);

        long timeStamp = nowSecond - BEGIN_TIMESTAMP;
        //2.生成序列号
        //2.1.获取当前日期，精确到天//因为用于我们的日期的编号,防止超过32位
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));

        //2.2自增长
        long count = stringRedisTemplate.opsForValue().increment("inc:" + keyPrefix + ":" + date);
        // 3. 拼接返回（高位时间戳 | 低位计数器）
        return (timeStamp << COUNT_BITS)  | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = "+second);
    }

}
